Add a PTY multiplexer (/dev/ptmx) device.

When you open /dev/ptmx, you get a file descriptor pointing to one of the
available MasterPTY's. If none are available, you get an EBUSY.

This makes it possible to open multiple (up to 4) Terminals. :^)

To support this, I also added a CharacterDevice::open() that gets control
when VFS is opening a CharacterDevice. This is useful when we want to return
a custom FileDescriptor like we do here.

1 files changed, 1 insertions, 1 deletions

diff --git a/Kernel/SlavePTY.h b/Kernel/SlavePTY.h
index 773dcee6b4..1b01219349 100644
--- a/Kernel/SlavePTY.h
+++ b/Kernel/SlavePTY.h
@@ -5,13 +5,13 @@
 class MasterPTY;
 
 class SlavePTY final : public TTY {
-    AK_MAKE_ETERNAL
 public:
     virtual ~SlavePTY() override;
 
     virtual String tty_name() const override;
 
     void on_master_write(const byte*, size_t);
+    unsigned index() const { return m_index; }
 
 protected:
     virtual void on_tty_write(const byte*, size_t) override;